Capacity of cdma2000 fixed wireless access system with transmit diversity

Abstract

The capacity gain expected from next generation CDMA (IS-2000) fixed wireless access (FWA) networks over current (IS-95) FWA networks is attributed to various factors e.g. fast forward power control and transmit diversity. We study the forward link capacity of a FWA system based on IS-2000 technology for voice traffic with and without space-time spreading (STS) transmit diversity. The study indicates that an urban IS-2000 FWA system using STS can carry about 10-12% more traffic than an urban IS-2000 FWA system not implementing transmit diversity. In suburban environments the gain from STS is on the order of 50%. FWA systems using IS-2000 without transmit diversity can carry about 23% more traffic per sector in the suburban environments than the urban environments. In all these cases we have assumed that sufficient Walsh codes exist to support the carried traffic. In practice, the finite number of Walsh codes may limit the capacity of many FWA systems.